I know folks who use standard size APP's in hotliner applications at up to 175 amps with no issue.

Originally Posted by mrforsyth

I know folks who use standard size APP's in hotliner applications at up to 175 amps with no issue.

How long they pulling 175A continuous for? I love APPs and use them where ever possible, but not sure I'd even try that.

Don't know for sure but I have seen videos of crimped APPs working just fine at loads that caused solder reflow and subsequent failure in equivalent soldered connectors (Deans, XT60, EC3, etc.).

Mark

Mark et al,

So why aren't APP's more prevalent in the hobby? Just going by what I see in that video, they *seem* to be a much simpler alternative to soldering connectors.

Originally Posted by Muddie

Mark et al,

So why aren't APP's more prevalent in the hobby? Just going by what I see in that video, they *seem* to be a much simpler alternative to soldering connectors.

They are quite popular, but it's a personal preference thing. Some also don't want to invest the money in the proper crimp tool.

Here's another excellent tutorial:

http://www.mpjet.com/cat/pages/21010mount_en.html

Originally Posted by Ohmic

Here's another excellent tutorial:

http://www.mpjet.com/cat/pages/21010mount_en.html

Not bad but can lead to cold or disturbed solder joints.

In my experience, both the wire and connector must be held stationary by a 'helping hands' or similar device that specifically prohibits movement when the solder solidifies. Relying on a human hand is asking for trouble as I see it. Also, jamming a cold wire into molten solder more often than not leads to a cold solder joint that can have a high resistance connection.

To make a far more consistent and reliable connection:

Pre-tin the contact by filling the contact with molten solder and then wick the solder out of the contact with solder braid, fully insert the tinned wire into the tinned contact and hold stationary with helping hands or alligator clip, heat the wire and contact with a tinned solder tip and then feed solder wire into the contact until full, and then remove heat and allow to solidify.

In my experience, the technique demonstrated by both Lucien and MP Jet both yield excellent results. I fail to see how your technique yields "a far more consistent and reliable connection". If you cannot hold the wire steady enough then by all means, use a helping hands device.

Perhaps you can post of video of your technique?

Originally Posted by mrforsyth

Not bad but can lead to cold or disturbed solder joints.

In my experience, both the wire and connector must be held stationary by a 'helping hands' or similar device that specifically prohibits movement when the solder solidifies. Relying on a human hand is asking for trouble as I see it. Also, jamming a cold wire into molten solder more often than not leads to a cold solder joint that can have a high resistance connection.

To make a far more consistent and reliable connection:

Pre-tin the contact by filling the contact with molten solder and then wick the solder out of the contact with solder braid, fully insert the tinned wire into the tinned contact and hold stationary with helping hands or alligator clip, heat the wire and contact with a tinned solder tip and then feed solder wire into the contact until full, and then remove heat and allow to solidify.

Thank you, Ohmic and Mark. Those last few posts have been very informative.

Filling the container with solder, then wicking it out is new to me, but I will add that step to my process and see if that improves the end result.

If I may venture off-topic for a moment, that process reminds me of another issue I run into with bullet connectors. The connectors I use have a hole in one side of the connector. When filling the container with molten solder, How do you prevent it from flowing out the hole? Seems I'm always fighting this and ending up with a lot of unwanted solder on the outside of the connector.

Bob

Originally Posted by Muddie

When filling the container with molten solder, How do you prevent it from flowing out the hole?

My means of dealing with this is to hold the pre-tinned iron against the side of the connector away from the hole, and then feed solder into the connector. Molten solder will always try to migrate toward the heat source so the problem you describe is minimized by orienting the heat source away from the hole. My other means of dealing with this is to no longer source connectors with big holes in the side.

BTW, tinning and wicking of the connector is not entirely necessary but will minimize the amount of gold in the resultant solder connection. Excessive gold causes brittle solder joints that can fatigue and fracture over time so it's best to remove it. This process is mandatory for high reliability military and space applications. For our hobby, it's obviously optional.

Mark

Originally Posted by Ohmic

In my experience, the technique demonstrated by both Lucien and MP Jet both yield excellent results. I fail to see how your technique yields "a far more consistent and reliable connection". If you cannot hold the wire steady enough then by all means, use a helping hands device.

Perhaps you can post of video of your technique?

Not 'my technique' per se but one that I learned ~25 years ago when I was sent to China Lake Naval Air Weapons Station to get certified to WS-6536 for high reliability soldering. Myself and several other engineers spent nearly a week being trained in high reliability soldering as part of contingency preparations for a possible strike at our military avionics assembly facility.

As the instructors had a tendency to hover over us while being certified, anyone caught making solder joints via the MPJet technique would be remedial trained and would be sent packing if caught a second time. This would have greatly displeased my leadership.

I will try to shoot some photos or make a video sometime.

Mark

Originally Posted by mrforsyth

Not 'my technique' per se but one that I learned ~25 years ago when I was sent to China Lake Naval Air Weapons Station to get certified to WS-6536 for high reliability soldering. Myself and several other engineers spent nearly a week being trained in high reliability soldering as part of contingency preparations for a possible strike at our military avionics assembly facility.

As the instructors had a tendency to hover over us while being certified, anyone caught making solder joints via the MPJet technique would be remedial trained and would be sent packing if caught a second time. This would have greatly displeased my leadership.

I will try to shoot some photos or make a video sometime.

Mark

Great! I look forward to the video demonstrating the technique you use.

Not a video but below is a macro image of a 12AWG wire / 4mm connector solder connection that I made earlier this morning with the above described technique.

Will have to dig out a tripod and figure out how to get a close up video. It's supposed to hit 80 degrees here today so my indoor activities are going to be limited...

Mark

I would definitely give that an A+

Thanks Ohmic!